American Kestrel (Falco sparverius), photographed at Point Reyes on 26 November 2014.
At a length of about 25 cm (or 10 inches), American Kestrels are the smallest of the North American falcons. Although they used to be called Sparrow Hawks, they're more often seen eating invertebrates (e.g., crickets and grasshoppers) and small mammals (e.g., mice and voles). On Bodega Head, I've occasionally see them eating lizards. Have you observed them with other prey?